Efficacy of immediate loading compared to conventional loading in implant-supported removable prostheses: a systematic review and meta-analysis

Purpose: This systematic review and meta-analysis aimed to evaluate the efficacy of two different loading methods in implant-supported removable prostheses (partial dentures and full-maxillary dentures). Methods: As of August 2023, three electronic databases and nine oral implant-related journals had been searched. Only randomised controlled trials (RCTs) that compare immediate loading with conventional loading in implant-supported removable prostheses were included. The primary outcome was the implant survival rate. At the same time, a meta-analysis of bone-level changes was performed. Cochrane risk-ofbias tool for randomised trials (RoB 2) was used to evaluate the risk of bias in the included trials. Results: A total of 16 RCTs were included, including 543 participants with 1595 implants. The included trials compared immediate loading and conventional loading in implant-supported removable prostheses. Regarding implants as the statistical unit, the immediate loading group had a statistically significant lower survival rate (RR = 0.950; 95% confidence interval [CI], (0.926, 0.974); P = 0.027; I2 = 47%). When patients were regarded as statistical units, a statistically significant lower survival rate was also observed in the immediate loading group (RR = 0.929; 95% CI, (0.897, 0.961); P = 0.590; I2 = 0%). When we analysed the bone level changes, a statistically significant decrease was observed in bone level in the immediate loading group compared with the conventional loading group (weighted mean difference [WMD] = -0.127; 95% Conclusion: Lower implant survival rates and a decrease in marginal bone level was observed compared to immediate loading with conventional loading.